Hi Roger -
At some point in the earlier days of the cold war, the Soviets decided to standardize the tram fleets in Russia and most of the Eastern European satellites, and picked the Tatra T1-T2-T3 models (and their articulated variants) as the choice. Probably the best decision those people ever made. Over 15,000 were built, far and away the most popular tram model ever produced and one of the longest-lived. They were well-built, reliable, and, with PCC "guts", as modern as anything around at the time. Many are still running in the former Iron Curtain countries, and, as far as I know, cities like Prague, Brno, and Bratislava use them and successor Tatra models exclusively. Ever the burr in Moscow's side, the Poles built their own version (by Konstal), but using the same technology, sublicensed from Tatra.
But obviously neither the politics nor the U.S. transit situation were conducive to any imports. The domestic market for PCCs was pretty much dead by 1948, and any operator in the U.S. that wanted PCCs afterward could pick up used cars cheap.
Several Western European cities also used PCCs, most notably Brussels, Gent, Antwerp, SNCV, and The Hague, built under license by the Belgian firm La Brugeoise.
Sadly, Tatra couldn't seem to compete in the present European tram market and is out of the business, although Skoda has had some slight success in the U.S.
Herb Harwood